JPH0651847B2 - Easy dispersible organic pigment - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention is characterized by containing at least one acidic amino acid derivative represented by the following general formulas (1) to (3) as a dispersant. Regarding the organic pigment, the organic pigment produced by the present invention is used in the fields of paints, resins, printing inks, rubbers, plastics, stationery, papermaking and the like.

(However, in the formulas (1) to (3), R and R ′ each have 6 carbon atoms.
.About.18 alkyl group or alkenyl group, and in the formula (3), X and Y represent hydrogen, methyl group, ethyl group or hydroxylethyl group. n represents 1 or 2. ) Conventional Technology Conventionally, as organic pigments used in the above-mentioned various fields, phthalocyanine pigments, dioxane pigments, quinacridone pigments, anthraquinone pigments, indigo, thioindigo pigments, quinophthalone pigments, azo pigments,
Examples thereof include perinone, perylene pigments, isoindolinone pigments, carbon black and the like.

In general, the color tone and tinting strength of these organic pigments depend largely on the particle size distribution, so they are used after being pulverized into a fine powder. However, it is known that the thus-obtained organic pigment has poor dispersibility and that pigment particles aggregate in a non-aqueous vehicle, resulting in uneven color and loss of gloss.

Therefore, various methods have been disclosed as methods for solving such problems. For example, a method in which a powder pigment is previously dispersed in a plasticizer into a paste by a flushing method or a grinding method is used for a long time. In addition, a method in which a water-containing cake of an organic pigment is suspended in an organic solvent using a surfactant, heated, filtered, washed with water, and dried (Japanese Patent Publication No. 40-1844),
A method of using a pigment composition obtained by mixing a pigment, a large amount of a water-soluble anionic activator, and a water-soluble polymer with water and spray-drying (JP-A-49-7887). Method of treatment with an agent (JP-A-51-
88523), a method of using a thermoplastic resin and a solvent (JP-A-51-54620), a method of flushing with a water-soluble thermoplastic resin and a pigment-containing cake (JP-A-54-95638), etc. Is disclosed.

Problems to be Solved by the Present Invention As described above, many inventions relating to the improvement of the dispersibility of organic pigments are found, but many problems remain. For example, in the case of containing an active agent as a dispersant,
When producing laminated paper, yellowing occurs, and when applied to printing inks, paints, etc., water repellency due to an activator and deterioration of printing characteristics become problems. Furthermore, a pigment composition using a thermoplastic resin requires a large amount of resin in order to disperse it uniformly. As a result, the pigment content decreases, and the coloring power decreases or it is applied only to a vehicle compatible with the resin used. The drawback is that it cannot be done.

Means for Solving the Problems As a result of intensive studies by the present inventors to solve such a drawback, as a result, an acidic amino acid derivative previously developed as a surface modifier for inorganic pigments (Japanese Patent Laid-Open No. 59-176377). JP-A-59-196367) and the like, and found that it exerts an epoch-making effect in improving the dispersibility of organic pigments in various media without causing water repellency and deterioration of printing characteristics. It came to completion.

That is, the present invention relates to a readily acidic organic pigment characterized by containing at least one of the acidic amino acid derivatives represented by the following general formulas (1) to (3) as a dispersant.

(However, in the formulas (1) to (3), R and R ′ each have 6 carbon atoms.
.About.18 alkyl group or alkenyl group, and in the formula (3), X and Y represent hydrogen, methyl group, ethyl group or hydroxylethyl group. n represents 1 or 2. ) To exemplify the above compound used in the present invention, N-
2-ethylhexyl aspartic acid-2-ethylhexyl ester, N-2-ethylhexyl aspartic acid lauryl ester, N-lauryl aspartic acid lauryl ester, 2-ethylhexyl aspartic acid stearyl ester, N-2-ethylhexyl aspartic acid-
2-ethylhexylamide, N-2-ethylhexyl aspartic acid laurylamide, N-lauryl aspartic acid laurylamide, aspartic acid-dilauryl ester, glutamic acid-distearyl ester, N, N-
Examples thereof include dimethylaspartic acid-dilauryl ester, N-methylglutamic acid-dipalmityl ester, N, N-bis-hydroxyethylaspartic acid-distearyl ester, and the above compound, if necessary, a metal salt or hydrochloride. Alternatively, it can be used as a salt such as P-toluenesulfonate. Such acidic amino acid derivatives are disclosed in JP-A-59-176377 and JP-A-59-176377.
It can be easily obtained by a known method described in JP-A-196367.

As a method for obtaining an easily dispersible organic pigment using the acidic amino acid derivative of the present invention, a dry blending method in which the acidic amino acid derivative is added to the organic pigment as it is, mixed by a pulverizer such as a ball mill, an atomizer, and a Henschel mixer, and co-pulverized, Or add it with an organic pigment in a suitable solvent,
A wet treatment method in which the solvent is removed after stirring and mixing is used. Further, when adding an organic pigment to a paint or resin, a method of directly adding an acidic amino acid and performing a mixing treatment with a ball mill, a hot roll or the like can be used. There are no particular restrictions on the form and particle size of the acidic amino acid derivative used in the present invention, and it may be used after being crushed or dissolved in a suitable solvent as necessary.

Examples of the organic pigment used in obtaining the easily dispersible organic pigment of the present invention include phthalocyanine pigments, dioxane pigments, quinacridone pigments, anthraquinone pigments, indigo, thioindigo pigments, quinophthalone pigments, azo pigments, and perinone. , Perylene pigments, isoindolinone pigments, carbon black and the like. Also,
The amount of the acidic amino acid derivative added to these organic pigments varies depending on the addition method, but is 0.5% to 20% with respect to the organic pigment in the dry blending method, and 0.1% to 10% in the wet method. Is usually used. Further, other surfactants that have been conventionally used, such as rosin soap, metal soap, sodium alkylbenzene sulfonate, and a condensate of formaldehyde and sodium naphthalene sulfonate, within the range that does not impair the effects of the acidic amino acid derivative. , Polyoxyethylene nonylphenyl ether and the like may be used in combination.

Effects of the present invention The organic pigment of the present invention includes ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, esters such as ethyl acetate, organic solvents such as hydrocarbons such as toluene, polyurethane resin, vinyl chloride-vinyl acetate. It disperses very well in resins such as copolymers, epoxy resins, phenol resins, acrylic resins, cellulose resins, polyamide resins and urea resins, and rubbers such as natural rubber, styrene-butadiene rubber and urethane rubber, and exhibits a vivid color tone. Moreover, since it has properties such as excellent water repellency and excellent printing characteristics that cannot be obtained by using conventional dispersants, it can be used in various fields such as paints, resins, plastics, printing inks, rubbers, stationery, and papermaking. Suitable for

Next, the contents of the present invention will be described in more detail with reference to examples.

Example 1 Water-containing cake of phthalocyanine blue (solid content 30%) 1
00 g is added to 100 ml of a 2 wt% N-2-ethylhexyl aspartic acid lauryl ester / methanol solution, stirred and mixed for 1 hour, filtered, dried, and ground. The phthalocyanine blue thus obtained was excellent in dispersibility in linseed oil varnish, mineral oil, etc., as compared with untreated one, and a clear and dense printing ink was formed.

Example 2 Shinkashared water-containing cake (solid content 25%) 100
g is added to 100 ml of a 2 wt% glutamic acid-dilauryl ester / methanol solution, and the mixture is stirred for 1 hour, filtered, dried, and ground.

The thus obtained Shinka Shared is excellent in dispersibility in toluene and spindle oil, and exhibits high water repellency, and is therefore suitable as a pigment for paints.

Example 3 Hydrous cake of phthalocyanine green (solid content 25%)
100 g was added to 100 ml of a 5 wt% N-methylglutamic acid-dipalmityl ester / methanol solution, and 1
After stirring for a while, the mixture is filtered, dried, and then ground. The phthalocyanine green thus obtained was excellent in dispersibility in toluene and spindle oil.

Example 4 15 g of N-lauryl aspartic acid laurylamide was added to 100 g of perylene red, and the mixture was mixed with a ball mill at 30 g.
After mixing for 20 minutes, 20 g is taken and mixed with 80 g of spindle oil for another 30 minutes on a paint shaker. When this is spread on paper using an applicator, it has a beautiful color tone with no color unevenness.

Example 5 5 g of N-2-ethylhexyl aspartic acid stearyl ester is added to 100 g of carbon black, and they are mixed in a ball mill for 30 minutes. Such carbon black has excellent dispersibility in mineral oil and is suitable as a pigment for printing ink.

Claims (1)

[Claims] 1. A dispersant represented by the following general formulas (1) to (3):
An easily dispersible organic pigment containing at least one of the acidic amino acid derivatives represented by. (However, in the formulas (1) to (3), R and R ′ each have 6 carbon atoms.
.About.18 alkyl group or alkenyl group, and in the formula (3), X and Y represent hydrogen, methyl group, ethyl group or hydroxylethyl group. n represents 1 or 2. )